Wired reported in 2012 the first successful prototype test of the military’s first-ever guided small-caliber bullets, developed by Sandia National Laboratories and Lockheed Martin. Around four inches long, the bullets feature optical tips to detect laser beams shown on targets. Actuators inside the bullets then steer tiny fins on their surfaces, which guide them to targets based on information from the tip sensors.

The bullets can strike a target accurately while accommodating for weather, wind, target movement and other factors, according to DARPA. The prototype tests were able to successfully strike targets from more-than a mile, or 6,500 feet away.

“For military snipers, acquiring moving targets in unfavorable conditions, such as high winds and dusty terrain commonly found in Afghanistan, is extremely challenging with current technology,” the agency explains on its website. “It is critical that snipers be able to engage targets faster, and with better accuracy, since any shot that doesn’t hit a target also risks the safety of troops by indicating their presence and potentially exposing their location.”

“The EXACTO .50-caliber round and optical sighting technology expects to greatly extend the day and nighttime range over current state-of-the-art sniper systems.”